Or just use this in your CSS:
h1
{
mc-auto-number-format: 'GH:{n+}. ';
}
h1.Appendix
{
mc-auto-number-format: 'GM:Appendix {A+}. ';
}
h2
{
mc-auto-number-format: 'GH:{n}.{n+}. ';
}
h2.Appendix
{
mc-auto-number-format: 'GM:Appendix {A}.{n+} ';
}
h3
{
mc-auto-number-format: 'GH:{n}.{n}.{n+}. ';
}
h3.Appendix
{
mc-auto-number-format: 'GM:Appendix {A}.{n}.{n+} ';
}
h4
{
mc-auto-number-format: 'GH:{n}.{n}.{n}.{n+}. ';
}
h5
{
mc-auto-number-format: 'GH:{n}.{n}.{n}.{n}.{n+}. ';
}
h6
{
mc-auto-number-format: 'GH:{n}.{n}.{n}.{n}.{n}.{n+}. ';
}
